[Insulin-like effects of agmatine derivatives in vitro and in vivo (author's transl)].

The synthesis and insulin-like effects of two new groups of agmatine derivatives are described. We prepared the N omega-isopropylagmatines (1-[omega-(isopropylamino)alkyl]guanidine) and the N omega-formylagmatines (1-[omega-(formylamino)alkyl]guanidine with the alkyl chain lengths varying from C4 to C8. For determination of glucose oxidation, we used isolated fat cells from rat epididymic adipose tissue; mice were used for in vivo determinations of blood glucose level and lactate concentration. Glucose oxidation is considerably increased by isopropylagmatines, hypoglycemic effects could not be observed. The lactate concentration of the serum is lowered. At agmatine chain lengths of C6 and more, subtoxic doses of formylagmatines depress the blood glucose level; the values were definitely hypoglycemic (20 to 30 mg/100 ml). Glucose oxidation is unaffected, or, in some cases, decreased. Lactate concentration is increased by formylagmatines. We did not succeed in finding an alkylated agmatine derivative with hypoglycemic activities which does not affect the production of lactate.